1. Field of the Invention
The present invention relates to a method of forming a carbon polymer film by plasma CVD using a hydrocarbon-containing material having high molecular weight, and more particularly to a method of utilizing the carbon polymer film as a hard mask for semiconductor processing.
2. Description of the Related Art
In semiconductor processing techniques, optical films such as antireflective films and hard masks are used. In conventional techniques, these films are formed mainly by a technique called a coating method. The coating method forms highly functional polymer films by coating a liquid material and sintering it. It is, however, difficult to form a thin film on a substrate because a liquid having viscosity is coated. As semiconductor chip sizes continue to shrink, more thinned and higher-strength films are required.
As an advantageous method for achieving thinner films, use of a DLC diamond-like carbon film or an amorphous carbon film by plasma CVD has been reported (e.g., U.S. Pat. No. 5,470,661, U.S. Pat. No. 6,428,894). In these cases, using a molecule which is gaseous at room temperature as a material, a diamond-like carbon film or an amorphous carbonous film is formed by decomposing the molecule by plasma. Using a plasma CVD method gives promise of facilitating to achieve thinner films.